1. Field of the Invention
The present invention relates generally to semiconductor device packages and, more particularly, to lead frame based semiconductor device packages including at least one passive device.
2. Description of the Related Art
In a conventional semiconductor device package, a housing encases the semiconductor device (die) to prevent damage to the die from exposure to the environment. The housing may be hermetically sealed, encased in plastic, or otherwise protected from the environment.
In lead frame based semiconductor device packages, electrical signals are transmitted between at least one die and external circuitry, such as a printed circuit board, by an electrically conductive lead frame. The lead frame includes a number of leads, each having an inner lead end and an opposing outer lead end. The inner lead end is electrically connected to input/output (I/O) pads on the die, and the outer lead end provides a terminal outside of the package body. Where the outer lead end terminates at the face of the package body, the package is known as a “no-lead” package, while if the outer leads extend beyond the package body perimeter the package is referred to as “leaded”. Examples of well-known no-lead packages include quad flat no-lead (QFN) packages, which have four sets of leads disposed around the perimeter of the bottom of a square package body, and dual flat no-lead (DFN) packages, which have two sets of leads disposed along opposite sides of the bottom of a package body. A method for the manufacture of a lead frame based package is disclosed in commonly owned U.S. patent application Ser. No. 10/134,882 that was filed on Apr. 29, 2002 and is incorporated by reference in its entirety herein.
In many electronic assemblies, passive components such as, for example, capacitors, inductors and resistors, are interconnected with semiconductor device packages to provide desired functions. Heretofore, most of these passive components could not be integrated within an encased die package in a cost effective manner.
It is desirable from both a manufacturer's and user's standpoint that electronic assemblies require as few as possible external connections since such connections increase manufacturing costs (that are ultimately passed to the user) and can introduce noise to the package as signals are propagated from external components.
Accordingly, the inventors have realized that a need exists for an improved semiconductor device package including a cost effective method for placing passive components close to a die and for encasing the passive components and die in a single package.